Concrete forms are molds that are used for building concrete walls, and are often employed in conjunction with building the foundations of residential and commercial structures. The concrete form defines a cavity that delineates the desired shape of the wall. Concrete is poured into the cavity and allowed to cure to construct the wall.
Concrete forms can be of the removable or permanent type. Removable concrete forms are built on site out of lumber and plywood or constructed from a modular steel frame. Once the concrete is poured and cured, the temporary forms are removed. Permanent forms are left in place after the concrete has cured. Permanent forms, such as insulated concrete forms (ICF's) made of rigid plastic foam, remain in place after curing to serve as thermal insulation for the concrete walls.
During the concrete curing process, chemical changes occur in the presence of water which ensures that the hardened concrete will be water-tight and durable. These chemical changes occur over a considerable period of time requiring that the concrete be kept wet during the curing period. The heat radiating from the concrete during the curing process evaporates the moisture in the concrete, inhibiting the chemical hardening process and compromising the strength and durability of the cured concrete. It is therefore necessary to contain the heat and moisture in the concrete long enough to permit the curing process to be sufficiently completed.
The need for heat and moisture retention increases during cold weather applications. ICF's are often used during cold weather curing processes to insulate the concrete, allowing the concrete to cure while isolated from outside temperature and moisture. Additionally, curing blankets or other insulating materials such as straw, sawdust, and the like are placed over the exposed surface of the concrete along the upper end of the concrete form which further insulates the concrete and protects it from moisture.
However, it is difficult to maintain the insulating materials in place during the entire curing process when there is strong wind, rain, or snow, as often is the case during cold weather. Various approaches have been taken in attempts to secure the insulating materials. For example, attempts have been made to secure the curing blankets by string or tape, but these approaches have not been very successful or efficient.
Thus, there is a need for an effective, efficient, and low cost means for attaching and retaining curing blankets over the upper end of a concrete form.